This application claims the benefit of the Korean Application No. P2002-23706 filed on Apr. 30, 2002, which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a dust collector which collects various dust produced at industrial sites for prevention of fly or scattering of the dust, and more particularly, to a dust collector with an assembly of cylindrical and hexahedral bag filters, of cloth of chemical fiber, natural fiber, or metallic fiber fitted in a filter housing for filtering the dust entering into the filter housing.
2. Background of the Related Art
In general, the dust collector is an apparatus for separating different dust (general dust, zinc oxide, fume, saw dust, cotton, shavings, grain dust, wool, lead dust, and the like) produced at industrial sites from air, to discharge cleaned air to the atmosphere, thereby preventing pollution of the atmosphere with dust. The dust collector employs a filter, or bag filter for filtering the dust.
The dust collector with the bag filter is basically provided with a plurality of cylindrical or envelope type bag filters fitted in a housing. In the dust collector, air containing dust is introduced into the housing, and discharged to an outside of the housing after the air passes through the bag filters.
A related art dust collector with cylindrical bag filters will be explained. FIG. 1 illustrates a section of a related art dust collector with cylindrical bag filters, and FIG. 2 illustrates a section of a key part of a related art dust collector with cylindrical bag filters.
As shown, the housing 1 in a hexahedral form is provided with a hopper 1a fitted to a bottom thereof. There is a bag filter holder 2 in the housing 1 for partitioning a lower part as a filtering and dust collecting region, and an upper part as a cleaned air discharge region. The hopper 1a has an inlet tube 3 connected thereto for introducing dirty air (air+dust) into the filtering and dust collecting region. The bag filter holder 2 has a plurality of cylindrical bag filters 4 each with opened top vertically fitted thereto for filtering the dust in the dirty air introduced into the filtering and dust collecting region of the housing 1 through the inlet tube 3. There is a rotary valve 5 fitted to a bottom end of the hopper 1a for receiving the dust filtered by the cylindrical bag filters 4 when the filtered dust fall down by gravity. There is an outlet tube 6 connected to a side of the upper part of the housing 1 opposite to the inlet tube 3 for discharging the cleaned air discharged to the clean air discharge region to outside of the housing 1. There is a compressed air supply tube 7 having a plurality of nozzles 7a above the bag filter holder 2 for receiving compressed air from an outside of the bag filter and supplying the compressed air to insides of the cylindrical bag filters 4. There is a fan 8 at an end of the outlet tube 6 for providing a discharge force of the clean air through the outlet tube 6 and a suction force of the dirty air through the inlet tube 3.
In installation of the related art dust collector with the cylindrical bag filters at an industrial site, it is required that an end of the inlet tube 3 connected to the hopper 1a is connected to a hood in a state the housing 1 is supported on a supporting plane.
Upon putting the fan 8 fitted to the outlet tube 6, air in the housing 1 is discharged outside of the housing 1 through the outlet tube 6, to drop a pressure inside of the housing 1 to generate a suction force. According to this, the dirty air is drawn into the housing 1 through the inlet tube 3 connected to the hood from a dust source.
Once the dirty air is introduced into the housing 1, a portion of the dust in the dirty air is fallen down and collected to the hopper 1a of the housing 1 by gravity, directly. However, most of the dust is moved upward toward the outlet tube 6 carried on the air, and passes the plurality of cylindrical bag filters 4, when the dust in the dirty air is filtered at the cylindrical bag filters. As the cylindrical bag filters 4 have opened tops, only clean air without the dust is discharged to the clean air discharge region, and discharged to an outside of the housing 1 through the outlet tube 6 as the fan 8 is operative, continuously.
In the meantime, when above operation is continued, there will be a state in which much dust is stuck to the cylindrical bag filter 4 such that a dust collecting efficiency is dropped due to an excessive pressure loss in the housing 1. If this state continues, the fan 8 at the outlet tube 6 is liable to be overloaded, and, when extreme, the motor on the fan is liable to be damaged. Accordingly, for preventing this state in advance, high pressure air (about 4-7 km/cm2) is blown to the cylindrical bag filters 4 periodically (3-6 min. interval), for removal of the dust stuck to the cylindrical bag filters.
That is, when an air compressor 9 provided on an outside of the housing 1 compresses air in response to a control signal of a controller (not shown), the compressed air is supplied to the clean air discharge region in the housing 1 through the compressed air supply tube 7, and blown downwardly through the plurality of nozzles 7a in the compressed supply tube 7. This high pressure air enters into the cylindrical bag filter 4 through the top opening, to make the dust stuck to the cylindrical bag filter 4 to fall off by the blow pressure of the compressed air and drop down by gravity. Eventually, as there is no excessive pressure loss in the housing 1 for a certain time period, the dust collector shows no deterioration of the dust collecting efficiency.
Most of the dust fallen off the cylindrical bag filter 4 drops by gravity and settles down so as to be collected in the hopper 1a, and is received at the rotary valve 5 under the hopper 1a. However, a portion of the dust fallen off the cylindrical bag filter 4 is flown again in a course of natural falling by the dirty air drawn into the housing 1 continuously through the inlet tube 3, and stuck to the cylindrical bag filter 4 again together with the dust in the dirty air.
In the dust collector with cylindrical bag filters, the opposite directions of the dirty air flow and falling off of the dust cause the following problem.
First, a portion of the dust fallen off the cylindrical bag filter by the compressed air can not fall freely but is laden on the dirty air, and stuck to the cylindrical bag filter, again. Consequently, the drop of filtering capability and the dust collecting capability cause an increased concentration of dust in the housing, as well as a pressure drop, that shortens a lifetime of the cylindrical bag filter.
Second, the downward blow of high pressure air for removing the dust from the cylindrical bag filter interferes with the dirty air moving upward toward the outlet tube 6. According to this, the dust stuck to the cylindrical bag filter, particularly, the dust stuck to a lower part thereof, can not be fallen off. Moreover, this becomes the worse, as a length of the cylindrical bag filter is the longer. Therefore, the length of the cylindrical bag filter can not but be short, to required an enlargement of a horizontal area of the body and increase a number of the cylindrical bag filter for obtaining a desired dust collecting effect. At the end, an occupied area of the dust collector is increased.
Third, even though a high capacity fan is required, which can provide adequate clean air discharge force through the outlet tube and dirty air suction force through the inlet tube, this increases an entire fabrication cost as components cost is increased.
Fourth, in the related art dust collector with cylindrical bag filters, since a lower end of the cylindrical bag filter is not held, though an upper end of the cylindrical bag filter is held by the bag filter holder, the cylindrical bag filters are shaken extremely, unable to achieve a stability, influenced by an air flow in a course the dirty air suction into the housing and the clean air discharge to the outside of the housing. Eventually, a lifetime of the bag filter is reduced.
Accordingly, the present invention is directed to a dust collector that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a dust collector which can recover dust laden on dirty air as well as dust removed from a bag filter without interference as the dust falls down by gravity.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the dust collector with an assembly of cylindrical and hexahedral bag filters includes a housing in a form of a hexahedral tank with a closed top having a hopper fitted to a bottom thereof, an inlet tube connected to one side of an upper part of the housing for introducing dirty air into the housing, a bag filter holding plate fixed to an upper part of an inside of the housing, a partition plate inside of the housing in a part the inlet tube is connected to the housing for isolating an upper region with reference to the bag filter holding plate from the other region, and guiding the dirty air introduced through the inlet tube downward directly, a plurality of cylindrical bag filters each with opened top and bottom held to the bag filter holding plate, for filtering dust from the dirty air introduced into the housing, a rotary valve fitted to a bottom end of the hopper for receiving the dust filtered by the cylindrical bag filters when the filtered dust falls down, and settled by gravity, hexahedral bag filters each formed as a unit with the cylindrical bag filters under the cylindrical bag filters for collecting clean air after the dirty air is filtered by the cylindrical bag filters, an outlet tube connected to one side of the hexahedral bag filters for discharging clean air collected in the hexahedral bag filter to outside of the dust collector, a fan at an end of the outlet tube for providing a discharge force through the outlet tube and a suction force of the dirty air through the inlet tube, and a compressed air supply tube having a plurality of nozzles above the bag filter holding plate for blowing compressed air from an outside of the dust collector to insides of the cylindrical bag filters in a vertical direction.
Preferably, each of the hexahedral bag filters includes a group of the cylindrical bag filters fitted thereto.
Each of the hexahedral bag filters is fastened to the housing, for stable holding of the hexahedral bag filters.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.